1. Field of the Invention
The present invention relates to a print control apparatus and a print method, and specifically, to a print control apparatus such as a host computer that controls a manner of printing in a printing apparatus such as a printer which carries out printing by switching a combination of the colors of printing materials used for printing such as toners and inks in accordance with an image to be printed. The invention also relates to a print control method for the print control apparatus.
2. Description of the Related Art
With progress in printing apparatuses based on an electro-photographic system or an ink jet system, the level of needs for the results of printing such as a printed image is increasing. As a configuration for meeting the needs, a printer has been proposed which carries out printing by using printing materials for the three primary colors of cyan (C), magenta (M), and yellow (Y) or the four primary colors including the three primary colors and black (K), as well as, print materials for particular colors, for example, red, blue, and green, or gold, silver, and a fluorescent color. A printing apparatus has also been proposed which carries out printing by using the above print materials for the primary colors as well as print materials for, for example, light cyan (LC) and light magenta (LM) which contain thinner coloring matters.
FIGS. 1 to 3 show specific forms of printing apparatuses having increased types of printing materials. All the forms shown in theses figures are printers based on the electro-photographic system. These printers use toners for six colors including C, M, Y, K, LC, and LM, as printing materials. The form shown in FIG. 1 is a printer employing six image carriers (photosensitive members) corresponding to the six toners. The form shown in FIG. 2 is a printer having six developing devices provided around the periphery of one photosensitive member. The form shown in FIG. 3 is a printed described in, for example, Japanese Patent Application Laid-Open No. 4-204871(1992) and employing two photosensitive members each provided with three developing devices around the periphery.
The printer shown in FIG. 1 comprises image forming sections Sa to Sf arranged along a conveyance path of an intermediate transfer belt 5 and having respective photosensitive members 1a to 1f for the corresponding printing materials and respective developing devices 41 to 46 in which the corresponding color toners are filled. This form provides a relatively high print output rate for six color printing and focuses on throughput or productivity.
In contrast, the printer shown in FIG. 2 has one photosensitive member 1 combined with six developing devices 41 to 46. A rotary 4 in which the developing devices 41 to 46 are mounted is rotated to selectively move the developing devices to a position facing to the photosensitive member 1, so that latent images are sequentially developed. Accordingly, with this configuration, a toner image developed as described above is transferred to the intermediate transfer belt 5 for each color, that is, a multi-transfer of the six-color toner image is carried out. The six-toner image formed on the intermediate transfer belt is then transferred to a print sheet. The printing apparatus based on this system provides a lower throughput than the form shown in FIG. 1 but has a relatively small size.
Further, the apparatus shown in FIG. 3 is a form corresponding to a compromise form between the apparatuses shown in FIGS. 1 and 2. Specifically, the apparatus shown in FIG. 3 has a first image forming section Sa including a photosensitive drum 1a and a second image forming section Sb including a photosensitive drum 1b. The image forming sections Sa and Sb are provided with three developing devices 41 to 43 and 44 to 46, respectively.
As described above, there are printing apparatuses using print materials for the four primary colors plus, for example, two print materials for particular colors or those having low depth of coloring matter, that is, a total of six color print materials. Some of these printing apparatuses can carry out printing by switching between a mode using only the print materials for the four primary colors and a mode using all the six color print materials. This is because printing with the four color print materials makes it possible to reduce the use amount of print materials as well as running costs, and particularly because in the configuration in which the rotary provided with the developing devices is sequentially rotated for printing as in the case of the form shown in FIG. 2, the reduced number of developing devices serves to improve the throughput.
Through a user interface such as the one shown in FIG. 4, the type of an image, on which determination as to whether to use the mode using the four color print materials or the mode using all the six print materials is based, is set. FIG. 4 shows a user interface provided by a printer driver in a personal computer. As shown in FIG. 4, setting of “Print Object” in “Print Quality” enables selection of the type of an image, for example, “Document/Table”, “DTP”, “Graphics”, or “Photographic Image”. Then, depending on this selection, the 4 color mode or the 6 color mode is specified, for example, as shown below, on the basis of a preset relationship.    Document/Table: 4 colors    DTP: 6 colors    Graphics: 6 colors    CAD: 4 colors    WEB page: 4 colors
As is apparent from the above relationship, the mode using the six color print materials is determined for an image that requires a relatively high image quality. The mode using the four color print materials is determined for an image that does not require a very high image quality.
The gradation of an image to be printed may be used as other reference for determining the mode. The mode is determined as described below by selecting, for example, “Panel Priority”, “Standard”, or “High Gradation” from a dialog for specifying “Gradation” as with the printer driver interface shown in FIG. 5.    “Panel Priority”: follows specifications for the standard and high gradation set in the panel of the printer    “Standard”: 4 colors    “High Gradation”: 6 colors
Also in this example, if a high gradation image, which requires a relatively high image quality, is printed, the mode using all the six color print materials is determined, as in the case of the example shown in FIG. 4.
Japanese Patent Application Laid-Open No. 2001-318499 describes a configuration similar to that described above. This document discloses an image forming apparatus that forms an image using a dark color toner and a light color toner. This image forming apparatus switches between a mode using only the dark or light color toner (corresponding to the above 4 color mode) and a mode using both dark and light color toner (corresponding to the above 6 color mode).
However, there is a problem with the printing apparatuses capable of carrying out printing by switching between a mode using a set of predetermined types of print materials and a mode using more types of print materials. That is, in particular, in printing in the mode using more types of print materials as in the case of the 6 color mode, the effects of the mode are not substantially obtained in connection with what is called the contents of “Page Setting” such as the layout of a page to be printed and a scale factor for an image to be printed.
For example, if the layout of the page to be printed is such that a plurality of images are printed within one page (one sheet) or a contraction scale factor is used, the size of each image is reduced. Thus, even though printing is carried out in the mode using more types of print materials as in the case of the 6 color mode, to obtain a high quality image, a user may not easily perceive the high quality when observing the print image. This problem also means that large amounts of print materials are consumed for the results of printing not always perceived as intended, and causes other problem of increasing the running cost relative to the image quality.
Besides the page layout, if for example, stamp printing for “Draft”, indicating that the image to be printed is a draft, is set, then in many cases, the image to be printed does not require a high image quality. In this case, if printing is carried out in a mode using more types of print materials as in the case of the 6 color mode, this mode is excessive in terms of the image quality. This also increases the running cost relatively to the image quality.
On the other hand, the image to be printed may be estimated to some degree depending on the setting of the size of a document or paper for printing or the scale factor in “Page Setting”. For example, if the setting for “Document Size” in “Page Setting” is “Postcard”, it can be estimated that printing with a somewhat high quality is desired when the postcard is printed in full colors. This also applies to the case in which an enlargement scale factor is used.